Did you know that Charles Fox, who wrote the Happy Days theme song, studied with the same woman who taught Leonard Bernstein, Aaron Copland and Philip Glass? Here's what he said about how the show started in this interview:
Love American Style had three separate segments, totally unrelated to each other - different stories, different casts. They were always called "Love and the..." something. I remember "Love and the Eskimo," I remember "Love and the Stuttering Cowboy," I remember all kinds of silly things. But this was called "Love and the Happy Days." And ABC made it a pilot at the same time, because it was a good way for ABC to develop a pilot and use it as part of the cost of Love American Style. They loved that show, but they decided that they weren't ready to re-visit the '50s, so they put it in the can until a year or two later when George Lucas's picture American Graffiti came out. And then they went back to what they already had in the can as a pilot, and the rest, as they say, is history.